Matin Ghazizadeh, S Roodgari, Maryam Ghazizadeh

Dear Editor,

We would like to present a rare case of lingual thyroglossal duct cyst (TGDC) in a 3-year-old male. His chief complaint was a recurrent mass in sublingual area. Other symptoms were drooling, swallowing difficulty and pain. His problems appeared 15 months ago. The case had been misdiagnosed as a sublingual abscess, so incision and drainage has been carried out. However, 3 months later, the swelling recurred and he was referred to us. A soft, fluctuant and tender mass was completely involved the sublingual area. There was a fistula in the midline of submental region. Thyroid function tests were normal. CT revealed a hypodense lesion with a rim enchantment (Figure 1). Also, the presence of thyroid gland in the normal position was confirmed by CT. Intra and extra-oral approaches were carried out under general anesthesia. A 5 cm x 4 cm sized cyst was completely excised intra-orally (Figure 2). Externally the fistula tract and the central portion of hyoid were resected through Sistrunk procedure. The tongue musculature had been displaced by the mass, without any involvement. So, there was no tongue deformity or speech morbidity postoperatively. TGDC was confirmed histopathologically. After 24 months the patient showed no recurrence.

TGDC is the most common congenital cyst in the neck which is usually located below hyoid (85%). Only 1-2% of cysts occurs around the tongue.¹ The main differential diagnoses of lingual TGDCs are ranula, mucocele, abscess, dermoid and epidermoid cysts.² Ultrasonography and CT scan are useful in diagnosis. Definitive diagnosis is histopathological.

In this case the mass was settled under the tongue which is very rare in TGDCs. Although Sistrunk procedure is the gold standard for management of all cases of TGDCs,³ practically it is difficult in the cysts involving the sublingual space.⁴ Also, a wide anterior neck dissection has been suggested for recurrent thyroglossal duct cysts.⁵

Lingual TGDC is a rare presentation of a common congenital malformation and should be considered if a young patient suffers from a sublingual mass.

Declaration of Interest

None declared.

Figure 1 CT with contrast shows a hypodense lesion with a rim enhancement involving the sublingual area.

Figure 2 The lesion is completely removed intraorally.

References

1. Zhang LC, Kang HY, Zhang TY, et al. Uncommon thyroglossal duct cyst with inward tendency: A recommendation regarding ingrowth type. Int J Pediatr Otorhinolaryngol 2012;76:322-6.

2. Hur JH, Byun JS, Kim JK, Lee WJ, Lee TJ, Yang HS. Mucocele in the Base of the Tongue Mimicking a Thyroglossal Duct Cyst: A Very Rare Location. Iran J Radiol 2016;13:e24827.

3. Gioacchini FM, Alicandri-Ciufelli M, Kaleci S, Magliulo G, Presutti L, Re M. Clinical presentation and treatment outcomes of thyroglossal duct cysts: a systematic review. Int J Oral Max Surg 2015;44:119-26.

4. Sameer KS, Mohanty S, Correa MM, Das K. Lingual thyroglossal duct cysts--a review. Int J Pediatr Otorhi 2012;76:165-8.

5. O'Neil LM, Gunaratne DA, Cheng AT, Riffat F. Wide anterior neck dissection for management of recurrent thyroglossal duct cysts in adults. J Laryngol Otol 2016;130:S41-4.